Theses and Dissertations (Centre for Wildlife Management)

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Wildness as a science-policy bridge for a better world
(University of Pretoria, 2024-03-27) Somers, Michael J.; Davies-Mostert, Harriet T.; mattychild@gmail.com; Child, Matthew
The world is losing its wildness – in the form of both wilderness areas and the ecological functioning of wildlife populations. While most literature investigates this loss as the negative consequences for biodiversity conservation and global conservation targets, especially through area-based conservation interventions, a more productive framing asks how the loss of wildness impacts socio-economic systems and how ‘rewilding’ can enhance society beyond the obvious benefits to biodiversity. In this thesis, I explore the concept of wildness as a ‘boundary object’ that can connect different stakeholders under a common conceptual paradigm and operate as a key science-policy-practice interface. Wildness does not exclude human influence or activity but positions the autonomy of ecological systems and human domination of systems on opposite ends of a spectrum. However, conservation science, and public perception of conservation, is trapped by a false dichotomy between intrinsic and instrumental value (largely mirroring non-human and human value), which has produced perverse policy and socio-economic feedback. Conservation policy and assessments, mostly originating in the global north, are narrowly centred on intrinsic values of biodiversity and present negative framings through messages of ‘extinction risk’ and ‘wildlife decline’ that presents wildlife and wildness as fragile entities not to be disturbed by humans. Such framings hinder socio-economic value creation and alienate conservationists from the other major counterfactual land-use – agriculture. Wildness transcends this dichotomy by integrating the innate ecological processes of wildlife and functioning ecosystems (intrinsic value) into effects and services that generate both individual well-being and socio-economic returns (instrumental values). I map potential pathways of how wildness and rewilding connect conservation value to these various dimensions of societal value across scales, using both expert-elicitation data and empirical data from surveys of private wildlife managers in South Africa, and contextualise these pathways within the wildlife economy. Beginning at the broadest scale, I discuss the various definitions of wildness and rewilding and construct a definition that articulates their boundary dimensions between conservation and policy, psychology and spirituality, agriculture and economics. I then construct a conceptual model, based on a literature review of nature’s contributions to people and capability theory from the social sciences, which demonstrates the infinite value of wildness to individual well-being and psychological functioning, focussing on wildness as a process rather than a pattern or place. I then translate wildness as a process into potential policy design and decision-making tools. Using the South African policy context as a case study, whilst drawing on my experiences in compiling the 2016 national Red List of Mammals of South Africa, I design a framework to measure the wildness of privately managed wildlife populations as a step towards mainstreaming local-scale assessments of conservation value into national assessments and market-based incentives; and use this framework to inform a potential wildlife economy certification scheme. I then apply this framework to privately managed Bontebok Damaliscus pygargus pygargus subpopulations to assess the prevalence of ecologically functioning herds on private lands and the potential for these assessments to unlock economic value through lowering the technical barriers needed to demonstrate conservation enhancement under trophy hunting regulations. Collectively, these results demonstrate the extent of wildness of private ‘working lands’ in South Africa, driven by socioeconomic conditions, where biodiversity conservation is an outcome rather than a primary goal. Simultaneously, they demonstrate the limitation of current conservation legislation and regulations based on Global North aspirations and paradigms. As such, I then assess the potential for wildness and rewilding to interface with multilateral agreements that focus on land restoration and sustainable land management as well as national agricultural policies that seek to improve land productivity and ecosystem condition. Specifically, I assess the impacts of converting from cattle farming to wildlife-based land-uses (WBLUs) on vegetation productivity dynamics at a national scale compared to counterfactual land-uses (commercial livestock farming, communal rangelands and formally protected areas), where I find that the rewilding of indigenous herbivore species significantly improves residual grassy productivity over time and slows the rate of woody plant growth, demonstrating the efficacy of rewilding in combatting bush encroachment in African rangelands and enabling the development of inclusive, production-based enterprises. I also find that increases in vegetation productivity correlate with increased profitability of WBLUs as does the use of fire, which underscores the importance of rewilding programmes to include restoration of natural disturbance regimes. Considering that climate change is making many rangeland areas less and less suitable for livestock farming, these results corroborate previous studies and opinions that WBLUs are an ecosystem-based adaptation to climate change. Importantly, my results also suggest that WBLUs function as a nature-based solution for climate change in that restoring ecosystem functioning is likely to actively sequester carbon dioxide into soils, which I explore further in a literature review of the impacts of rewilding on soil carbon sequestration. Finally, using survey data from new market entrants to the wildlife economy, I investigate the barriers to wildlife economy enterprise development and find there is conflict between the environmental and agricultural mandates, both conceptually and operationally, and argue that a pragmatic view of wildness and wildlife is needed to start ‘rewilding the commons’. Taken together, I conclude that rewilding can be reframed as a tool to improve agricultural productivity and enhance the resilience of rural production landscapes by diversifying revenue streams, but that mixed farms (combining wildlife and cattle or cultivation) should be seen as a strategic novel ecosystem and not just a transitionary land-use to wildlife-only protected areas. Considering this study's results, several themes emerge from viewing wildness as a boundary object with implications for wildlife economy development in African rangelands. Firstly, I suggest conservationists move away from a paradigm of ‘protecting and preserving wildlife’ towards a recognition of wildness and wildlife as assets in working lands that should be deployed to achieve positive socio-economic and social-ecological outcomes. This requires a shift in thinking from the vertical, top-down approach (current normative species-level assessments and regulations) to a horizontal, bottom-up landscape approach based on rewilding as restoration in novel ecosystems and an understanding of socio-economic systems as drivers of rewilding. Secondly, linked to this, is the need to transcend assessments of conservation value through Global North tools like the Red List, OECMs and non-detriment findings (under the Convention on International Trade in Endangered Species of Wild Fauna and Flora) to more proactive and locally relevant evaluations of wildness. The extension of ‘protected area thinking’ (species-level assessments, focus on static biodiversity features, emphasis on long-term legal guarantees) into working lands and commons is counterproductive in not understanding or recognising the drivers that lead to biodiversity conservation outcomes and feeds into public misinformation that in turn influences policy that negatively impacts sustainable use. Rather, seeing wildness and rewilding as inherently creative processes in novel ecosystems will free decision-makers to make more forward-looking policies and design market-based incentives that speak to impact investors. As such, thirdly, we must develop appropriate monitoring and evaluation frameworks to mobilise policy-relevant data. There is little evidence for the long-term impacts of rewilding on ecosystem and socio-economic system dynamics, and we lack fundamental information on the wildlife economy such as ‘what is it?’ (identification of viable business models and their impacts) and ‘where are they?’ (mapping the spatial extent of the sector and landscape-scale impacts), which leads to poor policy design as we cannot articulate the trade-offs or synergies between biodiversity, job creation and land productivity at multiple scales. Partnerships with private landowners are needed to document long-term dynamics, which must be facilitated through unlocking economic opportunities of wildlife. While the world is a significantly less wild place today than before the advent of neo-liberal market capitalism, restoring wildness, as a creative and unending process, provides hope that we can transition to ecological mindfulness and sustainable economic systems. “A ghost wilderness […] hovers around the entire planet,” wrote the poet Gary Snyder. It’s time for that ghost to guide us through the Anthropocene.
Implications of camera trap survey design and analytical methods for large carnivores estimates
(University of Pretoria, 2022) Keith, Mark; Somers, Michael J.; Venter, Jan A.; bairdtristan09@gmail.com; Baird, Tristan Daniel
Globally, carnivores face countless threats; and in some cases, these threats are worsened by a lack of population data. In South Africa, conservation has become largely confined to small, fenced, protected areas. It is well established that large carnivores play a vital role in ecosystems, providing valuable ecosystem services, i.e., herbivore regulation and meso-carnivore suppression. If populations are not adequately managed within these small, fenced protected areas, carnivores will place significant pressure on their favoured prey species, and in extreme cases, cause certain species to become locally extinct. For this reason, it is essential for conservation and wildlife managers to understand and monitor large carnivore populations, dynamics and the roles they play within the ecosystems. Estimating population sizes, abundances and densities for species that are difficult to identify (hereafter, unidentifiable), is difficult under conventional capture-recapture methods, leading to a sparse number of estimates on unidentifiable species. The implementation of camera trap methods has been developed and more readily implemented to bridge this knowledge gap, some of which were implemented in this study. Here, I estimated the population sizes of two species, leopard (Panthera pardus) and brown hyaena (Parahyaena brunnea), using camera trap count data from three camera trap projects, analyzed using the package ‘Unmarked’ in R-Studio. Camera trap data was supplied by three previously existing camera trap projects, i.e., Snapshot Safari South Africa, Panthera Organization, and a private baited and non-baited camera trap project. Data supplied were collected across three study sites, namely Madikwe Game Reserve, Pilanesberg National Park, and Atherstone Nature Reserve. The objective of this study was to determine the effect of three camera-trap deployment techniques on space use and density estimates of two large carnivores in Madikwe Game Reserve, Pilanesberg National Park and Atherstone Nature Reserve using unmarked analysis. In this study, I investigated the use of N-mixture models to estimate population sizes of leopard and brown hyaena and how different camera trap deployments influence the N-mixture model population size estimates. I compared N-mixture model population size estimates to pre-existing Bayesian closed-population capture-recapture estimates. Furthermore, this study aimed to provide empirical evidence supporting the use of N-mixture models to estimate the population sizes of both naturally marked and unidentifiable species. This study found that N-mixture models run using data from the sequential baited and non-baited camera trap deployment array and the roadside cluster deployment over-estimated leopard and brown hyaena population sizes across all the study sites. The regular deployment array provided 3 plausible estimates across all three of the fenced protected areas and were closely matched to previous population size estimates. The two targeted approaches, sequential baited and non-baited deployment, and roadside cluster deployment, were more efficient in collecting data. The targeted approaches recorded higher capture numbers and species detection probabilities. The evidence from this research cautions against the use of N-mixture models to conduct population analysis using camera traps due to the model sensitivity, seeing the models are reliant on detection probability and capture numbers.
Influence of bushmeat poaching and pastoralism on African lion Panthera leo (Linnaeus, 1758) ecology in rural Mozambique
(University of Pretoria, 2013-10) Somers, Michael J.; keveratt@gmail.com; Everatt, K.T. (Kristoffer)
The African lion, Panthera leo, has suffered dramatic population and range declines over the last few decades and is listed as Vulnerable to extinction by the International Union for the Conservation of Nature. Quantification of the factors limiting the abundance and distribution of lions in human disturbed systems is critical if we wish to promote the conservation of the species beyond the sanctuaries of a limited number of reserves. From September 2011 - November 2012, I studied aspects of the population and habitat ecology of lions in the developing Limpopo National Park (LNP), Mozambique; a woodland savannah ecosystem supporting relatively low prey densities and inhabited by subsistence-agro-pastoralisthunters.
Veldtipes, verspreiding van die groter soogdiere, en enkele aspekte van die ekologie van Kaokoland
(University of Pretoria, 1980) Bothma, Jacobus du P.; Theron, G.K.; Viljoen, Philippus Jacobus
Initiated in 1975, the purpose of this study was to obtain basic ecological information needed for the conservation, management and utilization of the fauna and flora of Kaokoland, S.W.A. Accordingly the vegetation of the area was classified into veldtypes and the status, distribution and movements of the bigger mammals were determined. To assist in the description of veld types, quantitative classification of the vegetation was based on the variable quadrant plqt method for trees and shrubs and the steppoint method for herbs. Information thus gathered was used to determine species composition and to estimate density per hectare, mean height, mean crown diameter, mean stem diameter, mean number of stems and canopy cover for the different plant species. In conjunction with bioclimatic and geographical divisions the above mentioned quantitative information of the vegetation resulted in the description of homogeneous vegetation units. In this way the vegetation was separated into fourteen veld types. The location, boundaries, topography, geology, soil, treestratum, shrubstratum, herbstratum for each veldtype and the major plant communities within each are described. In addition the vegetation of the drainage lines and the plants associated with springs are described. A synopsis of previous descriptions and classifications is also presented. It was found that the vegetation of Kaokoland ranges from a subtropical savanna with a maximum density of 2 085 trees and shrubs per hectare in the east to a nearly vegetationless desert with less than one shrub per hectare in the west. This gradient from east to west coincides with the gradient for rainfall. Some of the plant species occurring in each of the bioclimatic regions are specific for that region and ecologically adapted to it. Information on the bigger mammals was obtained through ground and aerial surveys conducted on a seasonal basis. Information collected included locality, numbers, habitat, distance from open water, group size and when possible also group structure, feeding and behaviour. This information was used to quantify the distribution and status of 36 species of bigger mammals. Social structure, habitat preference, movement and seasonal changes of the separate parameters were determined for the more common and easily observed mammals. Group structure, sex ratios, reproduction and feeding of some species are briefly discussed. Of the 36 mammal types studied, 21 are regarded as common, 6 as rare but in no immediate danger of extinction, the status of 3 as unknown, and 6 are regarded as highly endangered. The endangered types are Diceros bicornis, Aepyceros melampus petersi, Sylvicapra grimmia, Hippopotamus amphibius, Panthera leo and Lycaon pictus. Of these, two seem to be already extinct, i.e. Hippopotamus amphibius and Lycaon pictus. Because the different aerial surveys differ in time and space it was impossible to determine trends in game numbers. The results of the aerial surveys range from 2 256 bigger m~mals in the dry season to 8 006 in the rainy season. Therefore information on the past and present distribution of the various ma;nmals are used as indicators of trends. With the exception of single smaller antelope and predators, all bigger mammals show a decline in their range of distribution since 1970.
Aspects of the syntaxonomy and synecology of the grasslands of southern KwaZulu-Natal
(University of Pretoria, 1997) Bredenkamp, George J.; Granger, J.E.; Perkins, Luke
The Grassland biome of South Africa is ofmajor importance to this country's agriculture, mining and conservation practices. The extent of urbanisation and economic activity within this biome has led to the destruction or alteration of large areas of it, and concerns over this have led to the formation of a Grasslands Biome Project. A primary objective of the project is to improve our understanding of the workings of grassland systems, so that land use planning and conservation practices can be facilitated. The identification and description of major vegetation types and subtypes in the grasslands of southern KwaZulu-Natal forms part ofthis study. A total of547 sample riots were randomly distributed over an area of 14 000 km 2 between Estcourt and the Eastern Cape border. Stratification was based on Turner's Physiographic Regions ( 1967), Phillips' Bioclimatic Subregions ( 1973 ), and terrain units. The vegetation was classified by means of TWINSP AN and Braun-Blanquet procedures. Altogether 27 plant communities and 41 sub-communities were identified, described phytosociologically and ecologically interpreted. The diversity of these grassland communities was compared to that of grasslands in other parts of the country, and their conservation status was assessed in terms of land utilisation, endemism and biodiversity.
Viability, from a quality perspective on the reuse of wastewater effluents in the Southern Gauteng region, South Africa
(University of Pretoria, 2016) Du Preez, Hein; Skosana, Gugulethu Given
Growing populations, urbanization, environmental awareness with resultant regulations and water scarcity have resulted in a search for alternative water sources. Municipal wastewater reclamation and reuse is a necessity in these conditions because it is a water source that is available throughout the year. It can reduce the demand for source water and could be treated at lower costs to the required water quality requirements of the intended use. South Africa especially the Gauteng Province is subjected to the above mentioned stressors but lacks a holistic approach to wastewater reclamation and reuse as a practical and viable solution. Furthermore, the lack of characterization parameters as well as advanced wastewater treatment methods and the viability assessments of the municipal wastewater generated in the South Gauteng catchment, has led to loss of potential water resource in the province. Therefore the current research was initiated as a baseline study to investigate the feasibility of municipal wastewater reclamation and reuse in the South Gauteng catchment. The specific objectives were to 1) assess the worldwide practices of wastewater reuse, 2) apply influent and effluent data analysis and make recommendations on the type of reuse application available for the Southern Gauteng municipal wastewater treatment effluent and to 3) assess the viability of tertiary treatment technologies as best fit options available for different reuse options required for the study area. To achieve the above mentioned objectives a literature review was undertaken to assess worldwide water reuse practices and how they can be used in the study area to utilize the generated wastewater effluent. Influent and effluent data of four wastewater treatment plants (WWTPs) in the Sedibeng district municipality (SDM), three in the Emfuleni local municipality and one in the Midvaal local municipality, was used to assess the viability of water reuse. Available worldwide aggregate, nutrient, ionic and microbiological water reuse standards and criteria for potable, agricultural and industrial use were used to characterize the Sedibeng WWTPs for water reclamation. Wastewater reclamation and reuse is broadly defined as collecting treated or untreated wastewater and using it for a purpose different from what it was used for previously. Recycling, on the other hand, is using water, for the same purpose repeatedly (DWA, 2013a). Water reuse is practiced in countries such as the Western United States, Australia, Singapore, Namibia, Mediterranean countries and Japan for potable use, irrigation and industrial purposes. South Africa, having laid the foundation of wastewater reuse in Namibia, currently practices direct potable reuse (DPR) in the Beaufort West municipality as well as internal water recycling in the power, steel, petrochemical, paper and pulp industry. Water reuse standards and criteria are set based on regional differences of water availability, public health protection, monitoring feasibility, industry types and the reuse purpose. Risk assessment that includes among others a multi-barrier approach, water quality criteria objectives and acceptance determines treatment technology selection. Tertiary treatment technology such as ultrafiltration, reverse osmosis and advanced oxidation processes especially UV/H2O2 are used in water reclamation plants after preliminary treatment of secondary effluent. The four SDM WWTPs effluent, which was over 220 ML/d, the results show, mostly use activated sludge process and have water quality determinants complying with the design criteria for advanced treatment in water reuse. This effluent meets the Namibian Goreangab and Beaufort West Water Reclamation Plant (WRP) multi-barrier influent design criteria for DPR in most aggregate, nutrient and ionic parameters except microbiological parameters. Parameters such as chemical oxygen demand (COD), dissolved solids and ammonia and alkalinity were non-compliant for which this could signify incomplete activated sludge process. This shows the importance of secondary treatment as one of the barriers in the multi barrier approach. Even though membrane treatment of this effluent to improve these parameters and microbiological quality is possible effective secondary treatment as one of the barriers is important to prevent downstream membrane fouling. Depending on this water quality the water will be suitable for indirect potable reuse (IPR) with blending, industrial cooling, heat exchange and dust suppression as recommended uses. Municipal effluent, which could reduce potable water demand, is currently not used in the study area’s power generation and steel making industries Eskom’s Lethabo power station and ArcelorMittal respectively. This is even though, advanced water treatment processes such as reverse osmosis, exist for both organization’s internal wastewater recycling. The reclaimed municipal effluent can be introduced to moderate water quality processes such as cooling systems, heat removal, waste handling and washing in both industries in the study area. Public-private partnerships (PPPs) with water intensive user industries incorporating municipal secondary effluent in current and future infrastructure plans to find viable solutions as part of their water use licensing conditions. These PPPs would include the national Department Water and Sanitation (DWS), Sedibeng district municipality, Eskom, ArcelorMittal and Rand Water the bulk water utility in the study area. An in depth study of water reuse public perception, cost of water reuse, establishing purpose specific reuse guidelines and water quality monitoring and management plan for study area is recommended before implementation. Monitoring, which is one of the barriers in risk abatement, should include for the study area emerging pathogens, inorganic and organic contaminants of concern such as endocrine disrupting chemicals (EDCs).
Riglyne vir die bestuur van die natuurlewe in die bosveldgemeenskappe van die Atherstone Natuurreservaat in die Noordwes-Transvaal
(University of Pretoria, 1988) Bothma, Jacobus du P.; Van Rooyen, Noel, 1950-; Pauw, Johan C.
Philosophical, general, physiographical, climatological, biotic and plant ecological aspects as well as the availability of browse and the habitat preferences of the larger animals were investigated to serve as a basis for future wildlife management in the Atherstone Nature Reserve. General guidelines as well as guidelines for veld and game management are suggested. A monitoring program and the practical application of adaptive management are explained.
Aspects of the feeding ecology and behaviour of female leopards (Panthera pardus) in the Waterberg Mountains, South Africa
(2012-12-14) Van Hoven, Wouter; esmarie.jooste@gmail.com; Jooste, Esmarie
Leopards (Panthera pardus) have the widest distribution of any of the large cats in Africa and are found in habitats including savannas, deserts, forests and, mountains. Although well studied in savanna habitats, their feeding ecology and behaviour are still poorly understood elsewhere, especially in mountainous regions. Scat analysis and direct observations have been the most commonly used techniques to study leopard diet. However, leopards in mountainous areas hide their kills in dense vegetation or rocky overhangs and finding scats are difficult. All of these factors have contributed to the dearth of information on leopard diet and behaviour in these areas. This study investigated the general feeding ecology and behaviour of three female leopards in the Waterberg Mountains of South Africa. Leopards were fitted with global positioning system (GPS) collars and leopard feeding sites were identified and navigated to in the field using GPS cluster analysis. Over a five month period I investigated 200 potential leopard feeding sites and located 96 leopard feeding/kill sites. Prey remains were collected and analysed to determine gender, age, and subsequently mass of prey species. Together these data were used to estimate prey biomass intake of the leopards. The most frequently consumed prey species were impala (Aepyceros melampus), baboon (Papio ursinus), and klipspringer (Oreotragus oreotragus). Kudu (Tragelaphus strepsiceros) made the biggest contribution to the leopards‘ biomass intake, followed by impala and baboon. This study recorded the highest levels of predation on baboons to date, which may have significant effects on the population structure of these baboon populations. The management implications of seasonal predation on plains species in a mountainous reserve are discussed. Copyright
Biology and management affecting the decline of a black rhinoceros, Diceros bicornis minor (Linnaeus, 1758), population in Ndumo Game Reserve, KwaZulu-Natal, South Africa
(University of Pretoria, 2012-08-14) Somers, Michael J.; Van Rensburg, Berndt J.; Matthews, Wayne Sidney; Van der Westhuizen, Rickert
Black rhinoceros (Diceros bicornis) are classified as critically endangered on the IUCN red data list (IUCN 2010). In Ndumo Game Reserve in northern KwaZulu-Natal, South Africa, a black rhino population has seen a decline in numbers from nearly 50 rhino in 1988 to only eight in 2006. This study aimed to determine the factors or events responsible for the decline in black rhino numbers in Ndumo. The first part of this study focuses on the historical data and literature on Ndumo’s black rhino population. Specifically, I examined historical data regarding Ndumo’s black rhino population estimates, recruitment patterns, mortality rates, number of removals, introductions, densities and other large herbivore population estimates. Results suggest that a combination of high removals due to inaccurate estimates and competition from other herbivore populations, specifically nyala (Nyala angasi) and impala (Aepyceros melampus), played a role in this population’s decline. Also, a change in the Usuthu River course negatively affected the population’s social structure, movement patterns and recruitment success. The introduction of five black rhino from Hluhluwe-iMfolozi Park in 2008 seems to have been a success, and should increase reproductive success. Secondly, we determined the amount of browse currently (2008) available to black rhino in Ndumo, the proportional species composition of this browse and its suitability for black rhino. The results show that browse availability is fairly high (average of 17.8%) in Ndumo but the suitability is low. Croton menyhartii is the single biggest contributor to browse availability in Ndumo, contributing 25% of all available browse. This plant species is unfortunately rejected by black rhino and most other browsers. Furthermore, two invasive alien plant species (Chromolaena odorata and Lantana camara) are amongst the four most abundant plant species in Ndumo and are also rejected by black rhino. An effective alien plant clearing programme is needed to eradicate invasive alien species in Ndumo, which will help alleviate the poor browse conditions. A population viability analysis (PVA) was done during the last part of the study to predict the possibility of extinction or survival of this black rhino population in future. The VORTEX model was used in this study. Data and trends as actually observed in Ndumo since 1988 was used as the first simulation’s input parameters, to test whether the model will predict a similar decline in black rhino numbers as observed in Ndumo. Furthermore, sensitivity analyses with different input parameters were done to test the probability of extinction or survival under all possible circumstances. The model predicted a high probability of survival, even with most of the sensitivity analyses, suggesting that small populations of less than 50 individuals are viable if managed correctly. Parameters that impacted negatively on the growth rate of this population were density dependant breeding, a low recruitment rate and a decline in carrying capacity.
Interactions between habitat disturbances and complexity : the effect on ant communities
(University of Pretoria, 2011-08-08) jean_purdon@yahoo.co.uk; Purdon, Jean; Prof M J Somers; Dr C L Parr
Hluhluwe-iMfolozi Park is home to a number of indigenous and endemic species. As its mandate is to protect and preserve biodiversity, any factors that may result in the loss of species should be monitored carefully. This study aims to look at two such factors; the alien invasive plant Chromolaena odorata and intensive grazing by large mammalian ungulates (resulting in grazing lawns). Disturbances such as these typically result in the modification in University of Pretoria etd – Purdon, J. (2011) the structural complexity of the habitat which in turn affects its associated fauna. This study compared the structural change of these two disturbances and their adjacent uninvaded habitats and bunch grass habitats respectively. By using a set of manipulated and mensurative (natural) treatments the change in habitat structural complexity was then related to ant diversity, assemblage formation, competitive interactions, resource acquisition, resource monopolisation and ant body size. Both disturbances revealed that structural complexity within the natural experiments did not significantly alter ant assemblage composition, diversity or competitive interactions. However, at microhabitat scale, as was exhibited by manipulated treatments, structural complexity did appear to play a role in the organisation of ant communities, their competitive interactions and body size. The baited traps which were less complex in structure tended to support the larger species of ants which acquired resources at a faster rate and in higher numbers. Assemblage composition of ants and the diversity of ants were not significantly altered by C. odorata. This could suggest that ants respond to structural complexity rather than plant species richness. Therefore it would be wise to employ the use of other biological indicators such as spiders to test the effect of alien invasive plants on ecosystems. On the other hand, as a result of heavy grazing, a unique assemblage composition of ants was found on grazing lawns when compared with their adjacent bunch grass sites. This would suggest that grazing is a vital component of the savanna system as it adds heterogeneity to the system, resulting in a biodiversity increase. Copyright
Behavioural ecology, genetics and success of African wild dogs Lycaon pictus (Temminck, 1820) in KwaZulu-Natal, South Africa
(University of Pretoria, 2011-05-25) Somers, Michael J.; Gunther, Micaela Szykman; Maldonado, Jesus E.; Wildt, David E.; penners21@hotmail.com; Spiering, Penny A.
The African wild dog (Lycaon pictus) is one of Africa’s most endangered species, with fewer than 5,000 individuals surviving in the wild. Most of the remaining populations are increasingly fragmented and small, making loss of genetic diversity, reduced gene flow and inbreeding depression major concerns for the species. Recent efforts to conserve and increase severely declined numbers of wild dogs in South Africa have been focused on reintroductions to small protected areas to form a large metapopulation. The subpopulation in KwaZulu-Natal (KZN) was the first created and is currently the second largest population in the country with approximately 114 individuals. The overall goal for wild dog conservation in KZN is to establish a large, self-sustaining population within the province. This study evaluated the genetics and behaviour of the wild dogs in the province and explored how these factors influence long-term population health. An assessment of the progress made through reintroduction efforts to date was conducted by examining the current genetic diversity of the population and the pack and population dynamics shaping it. These findings were also used to investigate strategies for advancing the population to viable levels in the future. The scope of the project was divided into five topics to address the most crucial and intriguing aspects of African wild dog biology, conservation and management. First, non-invasive faecal genetic techniques were refined for field sampling of wild dogs in order to accurately genotype individuals and assess population heterozygosity. Second, the influences of inbreeding and genetic heterozygosity on fitness traits were investigated to determine if effects of inbreeding depression were apparent in the current population. Third, reproductive sharing among dominant and subordinate wild dogs was evaluated using genetic parentage analyses and long-term behavioural and demographic data. Fourth, the extent of inbreeding avoidance in wild dog reproduction was examined and the impact of this behaviour on future population persistence explored. Lastly, a population viability assessment using genetic inputs and goals was conducted for the current KZN wild dog population and strategies for the establishment of a viable future population were suggested. Genotyping and sampling errors were identified as significant sources of error in non-invasive analyses using faecal samples from wild dogs. Software assessments and replications were used to detect and correct genotyping errors. Sampling errors occurring in the field were corrected by evaluating multiple faecal samples from individual wild dogs, comparing matching individual blood and faecal genotypes, and using a large number of microsatellite loci to the identification of unique individuals in the dataset. Results showed that although genotyping and sampling errors were significant in our faecal DNA investigation of wild dogs, it is possible to correct these errors to generate consistent and accurate genotypes. Whenever possible, future genetic studies on African wild dogs and other endangered carnivores should apply these non-invasive techniques as they avoid handling of these stress-sensitive animals and have proven to be a reliable method of attaining good quality DNA. Though some cases of incest have been observed in the KZN wild dog population, the deleterious effects of inbreeding depression have only moderately begun to show on the lifespans of inbred individuals. Compared to non-inbred individuals, inbred wild dogs (f ≥ 0.25) had significantly shorter lifespans. However, this trend was limited to a small number of packs, indicating that although this seems to be evidence of inbreeding depression, a larger sample size is needed to confirm this. These results provide baseline data on the genetic diversity and fitness of the population and highlight the importance of tracking these characteristics in the future to ensure a healthy population. Within the parentage analyses, a substantial portion of reproductive sharing between dominants and subordinates was discovered in packs that contained siblings of the alpha pair. Alpha females mated annually, whereas subordinate betas bred in over half of all breeding years. Regardless of the number of adult males in the pack, litters of mixed paternity occurred in over 50% of years. Alpha males sired just over half of pups while one or two subordinate males sired the remaining pups in each pack. A skewed adult sex-ratio and frequent alpha mortalities for females and behavioural aggression in males allowed most individuals to attain dominant status in their lifetime. These findings suggest that more individuals than expected were able to contribute to reproduction in the population. In addition, reproductive partitioning in wild dogs is mediated through a combination of demographic, behavioural and hormonal factors. Extensive behavioural and genetic data confirm that wild dogs largely avoid mating with kin and suggest that avoidance is based on familiarity since only one inbreeding pair had prior association with each other. Computer-simulated populations revealed that preventing relatives from breeding could cause demographic declines and extinction due to an absence of unrelated mates. Although stronger inbreeding avoidance maintained significantly more genetic variation, small, isolated wild dog populations could encounter potentially severe demographic impacts of these behavioural mechanisms.
An ecological study of the plant communities of Marakele National Park
(University of Pretoria, 2009-03-02) Van Rooyen, Noel, 1950-; Bredenkamp, George J.; upetd@up.ac.za; Van Staden, Petrus Johannes
Please read the abstract in the section 06back of this document
Ecology, conservation and management of the black lechwe (Kobus leche smithemani) in the Bangweulu Basin, Zambia
(University of Pretoria, 2007-02-22) Van Hoven, Wouter; Bredenkamp, George J.; upetd@up.ac.za; Kamweneshe, Bernard Mwila
The black lechwe Kobus leche smithemani) is an antelope that belongs to the family reduncinae. Its current population is confined to the Bangweulu Basin in the northern Zambia. This research was undertaken to assess its current population status, the sex and age ratios, carrying capacity of the flood-plain where it occurs and its maximum sustainable yield. The study also estimated its potential sustainable off-take and looked into the links that exists between wildlife and socio-economics in order to demonstrate the views of local people on current wildlife management and utilisation. Historical records suggest that these antelopes were more widely spread and more numerous earlier last century. Until the 1930s the population may have numbered over 250 000. Records indicate major population decline during the first half of last century and therefore called for a quick management action. The population decline was thought to be caused by over-hunting and habitat change caused by an increase in water levels in the swamps. Aerial surveys during the 1950s suggested less than 20000 and by 1970 only 16 000 lechwe were counted from the air. From 1988-1996, ground surveys were undertaken with a four-wheel drive vehicle, on motor bike and on foot. A series of aerial censuses was also conducted during October, at the height of the dry season when the lechwe are relatively evenly distributed in the swamps, thus facilitating the use of stratified random sampling method. A fixed wing cessina 182 was used throughout the surveys. The study revealed that black lechwe is a highly prolific and resilient species. Its population has great potential to increase if given adequate protection and proper managed. Mating takes place on shallow flood-plains between November and April, but peaks in March. Receptive females leave their herds to join small breeding ground comprising few dominant males, which may be likened to leks formed by some other antelopes. The population of lechwe is currently maintained around 30,000. The sex ratio of the species is equal to unity and the age ratio was estimated at 3 : 1. The entire Bangweulu wetlands can sustain a population of at least 160 000 lechwe. A sustainable off-take of 6 000 individuals per annum was recommended. Black lechwe being an endemic species to the Bangweulu Basin is important for the economy of the country and the rural population. The study has revealed that local people are keen to participate in conserving it together with other species and the habitat as long as they are clear about benefits that they will gain from their effort.
Habitat utilisation, activity patterns and management of Cape buffalo in the Willem Pretorius game reserve
(University of Pretoria, 1999) Theron, G.K.; upetd@up.ac.za; Winterbach, Hanlie Evelyn Kathleen
The range use behaviour and activity patterns of a single herd of disease-free Cape buffalo Syncerus caffer in the Willem Pretorius Game Reserve, Free State, was investigated. This reserve falls outside the historical distribution of these buffalo. It has sub-optimal habitat for buffalo, a long history of severe overgrazing and no large predators. The veld condition and grazing capacity of six management units identified in the reserve were investigated, and a long-term grazing capacity of 750 L.S.U. calculated. A maximum long-term buffalo stocking rate of 82,2 L.S.u. was determined from their range use. The main factors, which appear to regulate habitat selection by the buffalo, are seasonal changes in the food supply, the availability of cover for daytime resting, and protection against low night temperatures. Effective management of the buffalo depends on protecting the woody riverbank and vlei grasslands, which are the most crucial vegetation types for the buffalo.
Ecological impact of large herbivores on woody vegetation at selected watering points in the Kruger National Park
(University of Pretoria, 2006-12-07) Van Rooyen, Noel, 1950-; Van Rooyen, M.W. (Margaretha W.), 1950-; upetd@up.ac.za; Brits, Jacques
Please read the abstract in the section 00front of this document
An ecological study of reintroduced Arabian oryx in the 'Uruq Bani Ma'arid protected area of the Kingdom of Saudi Arabia
(University of Pretoria, 2006-09-07) Bothma, Jacobus du P.; upetd@ais.up.ac.za; Strauss, Willem Maartin
This study was conducted in the ‘Uruq Bani Ma’arid Protected Area, on the western edge of the ‘Rub al Khali of the Kingdom of Saudi Arabia. The dispersal of different groups of Arabian oryx Oryx leucoryx (Pallas, 1777) was investigated, along with the seasonal range use patterns of the animals. The dispersal distances from the release site stabilised after a period of one year. The animals show seasonal differences in their range use patterns, associated with changes in their mobility. The dynamics of the relationship between the oryxes and their habitat were investigated. The structure and the condition of the vegetation, as well as some climatic variables were important determinants of seasonal habitat use. The diurnal activity patterns of the animals correspond with that characteristic of ungulates generally and the animals showed seasonal changes in their feeding preferences. The productivity of the population was high during the study period, with 34 live births, while six of the reintroduced animals died. Population viability analysis, however, shows that the population is vulnerable over the medium term (100 years) and that management should target the juvenile and especially adult females as they are keys to population growth and recovery.
The ecology of reintroduced lions on the Welgevonden Private Game Reserve, Waterberg
(University of Pretoria, 2006-09-07) Bothma, Jacobus du P.; Van Hoven, Wouter; upetd@up.ac.za; Kilian, Petrus Johannes
Five lions were reintroduced to the Welgevonden Private Game Reserve in 1998. These lions were studied to increase the limited knowledge of the ecology of reintroduced lions on small wildlife reserves, and to provide baseline data to the reserve management from which to develop management decisions. In the past, reintroduction attempts of felids have often failed because the animals failed to establish ranges in the new environment. During the current study, homing behaviour and range establishment of the reintroduced lions were studied and used as an indication of the success of the reintroduction attempt. The ease with which lions on Welgevonden established ranges indicated that they did not experience problems with adapting to their new environment The population dynamics of the reintroduced lion population were investigated. The population grew rapidly due to early breeding and short inter-litter intervals. The collected data were used to model the lion population using VORTEX population modelling software. Various potential management strategies to reduce the population growth were also modelled and discussed. The feeding ecology and predation patterns of the reintroduced lions• were investigated to give an indication of the predator-prey relationships on Welgevonden. These data were used in a model that investigated the effect of lion predation on the various prey populations of Welgevonden. The model was also used to test the influence of other factors on the prey populations, as well as the number of killing lions that can be supported by the prey population. The study has shown that reintroduction can be used successfully to establish a lion population on a small game reserve, but that certain management actions will increase the chances of success. However, continual monitoring and management will be necessary to ensure the long-term viability of the lion and prey populations.
Spoor density, movement and rehabilitation of cheetahs in Botswana
(University of Pretoria, 2009-09-04) Somers, Michael J.; amhouser3@yahoo.com; Houser, AnnMarie
The “vulnerable” listing by IUCN of cheetah Acinonyx jubatus in Africa has caused urgency in the protection of their habitat and development of predator management strategies. By understanding the movement and home range of cheetah in Botswana, translocation of problem cheetah or reintroduction of non-problem animals can be managed appropriately. More importantly this information will help to protect what is already there. Due to the increasing numbers of cheetahs being taken by illegal trade and poaching, there have become incidents of orphaned cubs where the only option for their survival is rehabilitation for release into the wild, or euthanasia. The first part of the study focuses on baseline information of movement patterns of cheetah in Botswana. Eleven cheetahs were collared and monitored from 2003-2007, including males and females with and without cubs from the Ghanzi and Southern districts. The understanding of cheetah movement is critical in determining methods of protection and survival of the species in protected areas living with competing predators such as lion Panthera leo, brown hyaena Hyaena brunnea and leopard Panthera pardus, as well as on farmlands where human conflict and habitat loss are the main causes of cheetah death. In the Southern district the cheetah were able to move freely in and out of the Jwana Game Reserve surrounded by communal livestock farms with low to medium conflict, utilizing various livestock protection methods, whilst Ghanzi consisted of livestock and game farms where conflict was high and protection methods were limited or nonexistent. Home ranges in males ranged from 492 km2(in single males) to 849 km2(in one coalition) in Ghanzi, while females ranged from 241 km2 to 306 km2 in Jwaneng. In addition, in order to determine the correlation between spoor density and true density, a 15 month spoor study was conducted in Jwaneng at the Jwana Game Reserve on a population of free ranging wild cheetah. A correction factor was tested and adjusted for accuracy, resulting in two formulas to be used in the wet and dry seasons. Spoor surveys are by no means a determinant factor, as they need to be repeated over time to observe population fluctuations due to outside factors, and are time consuming and can be expensive, but they are a management tool that can be utilized for estimations of cheetah densities on private farms or protected areas. The third part to the study was the rehabilitation of three orphaned cubs, from different families, that were put together from eight to twelve weeks old. The goal of this project was to raise and release fully functional, self sufficient, breeding animals into the wild population on a game farm. These cubs were raised in isolation until 1.5 years of age, then transferred to a 100 ha enclosure where they were given the opportunity to learn to hunt. Daily observations of their behavioural development and hunting abilities were recorded for 48 days and are presented in a descriptive way. At two years old they were released onto a 9000 ha game farm where their potential to survive on farmland was monitored. Botswana does not have the facilities or desire to keep predators captive, and if orphaned cubs could be utilized by placing them back into wild populations where they could add to the gene pool, alternatives would be available for captive bred animals or cheetahs facing life long captivity. Copyright
An ecological assessment of the sustainable utilization of the woody vegetation in the Lowveld Bushveld, Mpumalanga Province
(University of Pretoria, 2007-02-01) Van Rooyen, M.W. (Margaretha W.), 1950-; upetd@ais.up.ac.za; Rademan, Louise Katherine
This study was done in the communal area surrounding Makoko village and in the adjacent conservation area within the Kruger National Park, Mpumalanga province, South Africa. The structure of the woody vegetation within the two areas were compared in terms of species diversity, density, size structure distribution and biomass to determine the impact of fuel wood harvesting within the communal area upon the woody vegetation. There was no difference in woody plant species richness between the conservation and communal areas, but there was a difference between the uplands and lowlands. The conservation area uplands had the highest woody plant density and woody plant biomass. There were differences between areas in terms of the woody size class structure. The socio-economic status of Makoko village was determined by interviewing 100 households within the village. The use of fuels including wood, paraffin, candles and electricity was determined. Community and Kruger National Park issues such as advantages and disadvantages of living adjacent to the Kruger National Park were also noted. The demand for fuel wood within Makoko village was 338.9 kg per person per year, but the supply of fuel wood in the communal area was only 54.6 kg per person per year, if harvested sustainably. A conservation area of equal size could provide 270.0 kg of fuel wood per person per year on a sustainable basis. Management recommendations were made towards achieving sustainability in the use of the woody plant resources.
Utilization of the vegetation on Gabbro by Burchell's zebra and blue wildebeest in the Timbavati area
(University of Pretoria, 2007-01-31) Van Hoven, Wouter; Bredenkamp, George J.; Meissner, H.H.; upetd@up.ac.za; Bodenstein, Vanessa
The food selection pattern of zebra and blue wildebeest in terms of quality and quantity was studied in the Northern Province Lowveld on a site originating from gabbro geological formations. At the same time a comparison was drawn between the two species. The botanical composition of the grass layer in the study area was determined, the dominant species being Heteropogon contortus, Themeda triandra, Panicum maximum and Enneapogon spp. Forage selection and grass species utilized by the zebra and blue wildebeest were determined through the measurement of forage before and after grazing. The grass species P. maximum, H. contortus and Urochloa mosambicensis were mostly utilized by both zebra and blue wildebeest. Forage and faeces samples were hand collected. Regression equations were used to calculate intake from the average amount of grass species utilized (difference before and after grazing). The monthly dry matter intake as calculated through the plant based technique, did not compare well with the monthly dry matter intake as calculated through the animal based technique with an R2 value of 0.48. Although monthly differences in quality parameters of forage occurred, the same quality and quantity of forage were available for both animal species at a specific time during the sampling period. The mean lignin (ADL) content of the available forage utilized was 8.04 % for zebra and 8.17% for blue wildebeest with the mean in vitro digestibility of organic matter of the forage being 44.2 % (zebra) and 43.1% (blue wildebeest) respectively. There was a significant (p<0.05) difference in the mean intake (expressed as % of body weight) between zebra (2.58%) and blue wildebeest (1.80%). The mean in vivo digestibility of the dry organic matter (DOM) for the zebra (42.2%) was significantly (p<0.05) lower than that of the blue wildebeest (47.9 %) as well as the fibre (NDF) digestibility (respectively 38% and 49%). The climatologically dry conditions under which the study was done did not represent a typical year, and therefore the results were not used to test the carrying capacity equivalents that are officially being used for game animals. The quantitative results, however, confirmed contentions of other literature.

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